The hosts took the lead after six minutes, thanks to a goal from striker Ahmed Abdul-Zaher.
Mahalla's Mohamed Al-Etrawi leveled the score two minutes before the break and Abdul-Rahim Taha put them ahead on 50 minutes.
Central midfielder Mostafa, one of ENPPI's few consistent players this season, secured a share of spoils one minute from time.
ENPPI, who failed to maintain a promising start to the season, extended their winless streak to three games to virtually lose hopes of competing with leaders Ahli for the league title.
They lie eighth in the 16-team table with 11 points, nine behind defending champions Ahli. Mahalla are third from bottom on seven points.
Earlier in the day, Harras Hodoud moved into sixth place with a 1-0 victory over Asyut Petroleum.
Touch-tackling midfielder Mohamed Halim scored the winner after 38 minutes.
Hodoud's influential duo Abdul-Salam Nagah and Hani Saied, who fell out of favor with coach Tarek Al-Ashri after refusing to extend their deals, returned to the starting line-up.
They are expected to join Zamalek when the transfer window reopens in January.
Hodoud, who won the Egyptian Cup last season but are yet to impress this term, are sixth in the table with 12 points from eight games.